1. Field of the Invention
The present invention relates to a paging receiver, particularly to a paging receiver having a plurality of alert means.
2. Description of the Prior Art
Hitherto, when a paging receiver of this type detects a paging call including the call number of its receiver, the paging receiver reports to its carrier the reception of the paging call by driving a plurality of alert means, combining such alert means as an auditory alert means that sounds a buzzer, a tactile alert means that activates a vibrator (VIB), and a light-emitting visual alert means that activates a light-emitting diode (LED) or the like. In recent years, the receiver is provided with a liquid crystal display (LCD) so as to immediately relay messages to the carrier.
Such paging receivers are disclosed in "Information Display Pager" in NEC Research & Development No. 77, pp. 70-79, April 1985. The pager is equipped with an alert tone, an LED and an LCD. In addition, a paging receiver is disclosed in U.S. Pat. No. 4,918,438 (Apr. 17, 1990) which is equipped with a VIB drive unit and a loudspeaker drive unit, and these two alerts are activated sequentially in order to ensure that the carrier is alerted of the reception of paging calls. Hence, paging receivers equipped with LED and LCD in addition to a VIB or a loudspeaker are now in wide use.
Power consumption of paging receivers has increased with the provision of a plurality of alert means and message display means described above. Particularly, since a VIB has a motor drive and continuously consumes a large current from the battery, lengthy consecutive operation of the VIB may possibly deteriorate the battery life of the paging receiver, and further, anomalous operation of the paging receiver may possibly be caused when it is operated with a battery of reduced capacity. The duration of reporting of received calls is lengthy when approximately simultaneous calls from a plurality of callers are received, and in addition, when a receiver with message display means receives a long message from one caller that is divided and transmitted in several batches. For example, when a number n of succeeding calls including 1/n of one message each are received, a plurality of alert means are operated consecutively over n times the duration of the predetermined time period for reporting the reception of one paging call (for example, 20 seconds) if reporting is not stopped by the carrier. In the present invention, only one alert entailing minimum power consumption is activated for reporting the reception of succeeding paging calls.